Cervical cancer is detected through screening tests that check for abnormal cells or the virus that causes them, followed by closer examination if anything unusual turns up. The two main screening tools are the Pap smear and the HPV test, and most people between 21 and 65 need one or both at regular intervals. Here’s what each test involves, what happens if results come back abnormal, and how often you actually need to be screened.
The Two Main Screening Tests
A Pap smear and an HPV test look for different things, even though both use a small sample of cells collected from your cervix during a pelvic exam.
A Pap smear (also called a Pap test) examines cells from your cervix under a microscope to check for abnormal changes. These changes, called precancers, can develop years before actual cancer forms. Catching them early is the whole point of screening. A single Pap test picks up high-grade precancerous changes about 55% to 80% of the time, depending on the study and the thresholds used.
An HPV test looks for DNA from high-risk strains of human papillomavirus in your cervical cells. Nearly all cervical cancers are caused by HPV, so finding the virus early flags people who need closer monitoring. HPV testing is significantly more sensitive than the Pap smear alone, detecting high-grade precancerous changes 84% to 97% of the time. In one large randomized trial, HPV testing caught 95% of significant lesions compared with 55% for the Pap test. The tradeoff is that HPV testing is slightly less specific, meaning it produces a few more false alarms (94% specificity versus 97% for the Pap).
Some providers order both tests at once, which is called cotesting. Others use the HPV test on its own as the primary screen. Both approaches are considered acceptable for people 30 and older.
What the Screening Appointment Feels Like
Whether you’re getting a Pap smear, an HPV test, or both, the cell collection process is the same. You lie back with your feet in supports, and your provider inserts a speculum into your vagina to gently widen the walls. The widening is typically less than an inch for a routine screen. Your provider then uses a small brush or spatula to sweep cells from the surface of your cervix. The whole collection takes under a minute. You may feel pressure or a brief scraping sensation, but it shouldn’t be painful.
Those cells go to a lab, where they’re either examined under a microscope (Pap), tested for HPV DNA, or both.
Self-Collection Is Now an Option
In 2024, the FDA approved a self-collected vaginal swab for primary HPV screening in healthcare settings. This means you can collect the sample yourself rather than having a clinician use a speculum. The test is approved for average-risk individuals who don’t have a history of abnormal results. If you’ve had prior abnormal screenings or cervical treatment, a clinician-collected sample is still preferred because there isn’t enough data yet on self-collection for those situations.
How to Prepare for Your Test
For the most accurate results, avoid intercourse, douching, vaginal medicines, and spermicidal foam for two days before your appointment. You don’t need to do anything else special. You can schedule the test at any point in your cycle, though some providers prefer to avoid heavy menstrual days since blood can make cells harder to read.
Recommended Screening Schedule
How often you need screening depends on your age and which test you’re getting. The U.S. Preventive Services Task Force recommends:
- Ages 21 to 29: Pap smear every 3 years. HPV testing alone is not recommended in this age group because HPV infections are extremely common in younger people and usually clear on their own.
- Ages 30 to 65: Three options. A Pap smear every 3 years, an HPV test alone every 5 years, or both tests together (cotesting) every 5 years.
- Under 21: No screening recommended, regardless of sexual activity.
- Over 65: Screening can stop if you’ve had adequate prior screening with normal results and aren’t at high risk.
If you’ve had a hysterectomy that removed your cervix and you don’t have a history of high-grade precancerous changes or cervical cancer, screening is no longer needed. If your cervix was left in place (a partial hysterectomy), you still follow the regular schedule.
What Abnormal Results Mean
An abnormal Pap result doesn’t mean you have cancer. It means some cells looked unusual, and the next step depends on how unusual they are.
The mildest finding is called ASC-US, which stands for atypical squamous cells of undetermined significance. It means some cells looked slightly off but not clearly abnormal. Your provider will typically order an HPV test if one wasn’t already done. If HPV is negative, you can usually return to routine screening.
A result of LSIL (low-grade squamous intraepithelial lesion) means mild cell changes were found, often associated with an HPV infection. Most of these resolve without treatment, especially in younger people, but your provider will want to monitor you more closely.
HSIL (high-grade squamous intraepithelial lesion) is more significant. It indicates moderate to severe cell changes that have a higher chance of progressing to cancer if left untreated. This result almost always leads to a colposcopy.
A finding of atypical glandular cells (AGC) involves a different cell type in the cervix and may require both a colposcopy and additional sampling from the cervical canal.
Colposcopy and Biopsy
A colposcopy is the next step when screening turns up something that needs a closer look. It’s not surgery. It’s an examination that uses a magnifying instrument called a colposcope to give your provider a detailed view of your cervix.
The setup is similar to a regular pelvic exam. A speculum holds the vaginal walls open, and the colposcope sits just outside your body, shining a light onto the cervix. Your provider applies a mild vinegar-like solution to the cervix with a cotton swab. This solution causes abnormal areas to turn white, making them easier to identify. You may feel a slight burning sensation from the solution.
If abnormal areas are visible, your provider takes a biopsy, removing a tiny piece of tissue for lab analysis. This feels like a pinch or a brief cramp. In some cases, cells are also collected from inside the cervical canal using a small scraping tool, a procedure called endocervical curettage. The tissue samples are sent to a pathologist who determines whether the changes are precancerous, how severe they are, or whether cancer is present.
Results from a colposcopy biopsy are what ultimately confirm or rule out cervical cancer. Depending on the findings, next steps range from monitoring with repeat testing in a year to treatment procedures that remove the abnormal tissue before it can progress.